Isabella Dam set to undergo major operation to prevent failure, flooding

by Jeff Platt, Eyewitness News

FILE -- Water is released from the Isabella Dam in Kern County, Calif., Monday, Feb. 27, 2017. (KBAK/KBFX photo/Carol Ferguson)

KERNVILLE, Calif. (KBAK/KBFX) —

Isabella Dam and the Auxiliary Dam have both been monitored and studied for the better part of the last decade in efforts to determine how to prevent the old reservoir system from failing.

The dams were built properly back in the day and aren't failing now, but the U.S. Army Corps of Engineers knows a lot more now than was known when the dams were built more than 50 years ago.

Presently, Isabella Dam is at risk of failing for a number of reasons.

First and foremost, it turns out the dam sits on an active fault line, which could cause an earthquake and crack the dam, unleashing all the water behind it.

Second, the watershed, which feeds to Isabella Lake, is much larger than originally thought. It's actually larger than the state of Delaware. This means the dam could theoretically face more water than it can hold, and water could go straight over the top.

Also, there is a concern of seeping. While all dams allow some water to seep through, Isabella Dam allows to much, which could lead to erosion of the dam walls.

In all three of these scenarios, the dam fails, water comes rushing out uncontrolled, and a regional catastrophe floods the homes of more than 300,000 people and wipes out Bakersfield.

"We designated this dam as a dam safety action Classification 1, which is the highest, urgent and compelling risk," said Sam Winder, senior project manager for Isabella Dam.

In order to correct all of the safety and failure concerns, much work needs to be done to the dam.

The walls will be raised 16 feet. The current spillway will be redone. A new 300-foot wide spillway will be constructed. The dam will be fortified to withstand seismic shock.

All of this will take time and money. The project is currently slated for completion in 2022 and has a maximum budget of $500 million.

The project will also take a lot of patience from those who live and run businesses near the lake. To accommodate the construction, certain recreational facilities will be closed.

"Part of the project will be shutting down Boat Launch No. 19 temporarily," Winder said. "It is in our work area. Because of that, we're constructing a boat launch at the French Gulch recreation area."

The boat launch at French Gulch is anticipated to cause hefty traffic delays and impact. In preparation for this, turning lanes are being added in and out of the recreational area.

Locals have voiced their many concerns with the work but understand their discomfort is the price to pay for preventing a catastrophe.

Although work on the dam hasn't begun yet. they've already endured a good amount of disruption.